CHARLOTTE, N.C. (AP) — Tony Stewart will miss the start of his final NASCAR season after fracturing his back in an accident on an all-terrain vehicle, Stewart-Haas Racing said Thursday.

The three-time NASCAR champion sustained a “burst fracture of the L1 vertebra” when he crashed on an ATV Sunday and he had surgery Wednesday, the team said. A timetable for Stewart’s return has not been determined, but SHR said he is expected to make a full recovery and race this year.

Drivers report to Daytona next week to begin preparations for the season-opening Daytona 500 on Feb. 21. An interim driver for the No. 14 Chevrolet was not named Thursday.

Denny Hamlin in 2013 suffered a compression fracture to the same L1 vertebra and missed four races. But even after his return, he struggled with back pain the rest of the season.

Stewart will miss what was expected to be his final Daytona 500. He is 0-17 in the prestigious race and spoke last month about how it’s one of the few glaring holes on his resume. Stewart, who turns 45 in May, plans to retire from NASCAR competition at the end of this year.

Stewart was with Greg Biffle and other NASCAR personalities on the ATV outing in the Southern California desert when he crashed. The team said he was awake and alert as he was taken to a hospital and he was able to move all of his extremities.

Stewart flew to North Carolina late Tuesday and remained hospitalized Thursday following his surgery.

Biffle was not present when Stewart crashed but told SiriusXM’s NASCAR channel that “we started kind of hearing bits and pieces that he hurt his back.”

“I do know the people that helped him … (said) he was walking and moving all of his extremities, but he was in a lot of pain,” Biffle said.

This is yet another setback in the final stages of one of the most storied careers in racing. Stewart has slumped since breaking his leg in a 2013 sprint car accident. A year later, he missed three races while in seclusion after his car struck and killed a fellow driver at a dirt track in New York. Stewart was cleared of any criminal wrongdoing, but faces a civil suit from the family of Kevin Ward Jr.

He has not won a race since 2013, before he broke his leg, and was 28th in the final Sprint Cup standings last year. He had just three top-10 finishes and 24 laps led, both career lows, and readily admitted his confidence was shot.

A crew chief change was made for this season — the fourth different team leader Stewart will have since he won the 2011 title — and he hoped a new NASCAR rules package would better fit his driving style and make him competitive in this final hurrah.

No matter what happened this year, Stewart insisted last month this will be his final NASCAR season.

“If it’s a terrible year, I’m not going to sit there and go, ‘Wow, that defined my career,’ because the stats will show what we did over 18 years,” Stewart said. “I think no matter how the season goes, I’m going to be able to say I had a successful run in the Sprint Cup Series.”